Reigning weightlifting champions
A reigning champion is a champion who's won both the previous and current years' competitions. To determine if a champion is reigning, the previous and current years' results need to be in the same row, in two different columns.
Latihan ini adalah bagian dari kursus
PostgreSQL Summary Stats and Window Functions
Latihan interaktif praktis
Cobalah latihan ini dengan menyelesaikan kode contoh berikut.
SELECT
-- Return each year's champions' countries
___,
___ AS champion
FROM Summer_Medals
WHERE
Discipline = 'Weightlifting' AND
Event = '69KG' AND
Gender = 'Men' AND
Medal = ___;